CalDav Support

As of Zimbra 5.0 there is native CalDav support. The link below includes instructions on how to configure Zimbra CalDav for Apple iCal.

CalDAV_with_Leopard_iCal

For information on using Thunderbird/Lightning with Zimbra visit Accessing_Zimbra_Collaboration_Suite_with_Thunderbird or Thunderbird & Lightning.

mod_dav support in tomcat would be a starting point:

http://tomcat.apache.org/connectors-doc-archive/jk2/jk2/davhowto.html